test_that("quietly captures output", {
  f <- function() {
    cat(1)
    message(2, appendLF = FALSE)
    warning(3)
    4
  }
  expect_output(quietly(f)(), NA)
  expect_message(quietly(f)(), NA)
  expect_warning(quietly(f)(), NA)

  out <- quietly(f)()
  expect_equal(out, list(
    result = 4,
    output = "1",
    warnings = "3",
    messages = "2"
  ))
})